Dam



July 14, 1931. c. F. GRGNER DAM Filed June 11. 1929 Patented July 14, 1931 UNITED STATES PATENT? OFFICE Application filed June 11,1929, Serial No The present invention relates to an improvement in dams, and the object of the invention is to provide improved means for repairing leaking dams.

In cases where old dams of stone, concrete or the like have developed leaks, it is customary to repair the same either by the injection under pressure of a suitable concrete mixture in the body of the dam, or by providing the upstream face of the dam with a fresh water tight layer of concrete.

None of these methods are quite satisfactory, the injection system being very expensive and not thoroughly reliable, and the other system having the drawback that the contractions and expansions of thelayer on the up} I stream face of the dam differ from those of the dam itself, so that fissures and ruptures of the new layer will develop.

In accordance with the present invention the reconditioning of a leaking dam takes place by placing on the upstream side of the dam a thin water tight wall which is supported by the dam itself in such a manner that it is free to expand and contract in its own'plane independent of the dam.

It is preferred to erect the new tight wall at a certain distance from the upstream face of the old dam, the pressure on the water tight wall being transmitted to the dam proper by means of columns distributed overthe pressure area and being adapted, owing to their own elasticity or to their connection with the dam and tightening wall, to yield in planes 1 Vertical to their axis.

The tightening wall may, however, also be erected in close proximity to the upstream dam face, so long as the pressure transmitted from the tightening wall to the upstream dam face is taken up by means which permit the contraction and expansion of the tightening wall in its own plane independent of the dam.

An embodiment of the invention is illustrated on the drawing, showing diagrammatically a cross section through a dam repaired in accordance with the present invention.

1 indicates the dam to be repaired and 2 is a tightening wall which may be constructed of reinforced concrete, sheet iron or other material, and which is preferably tightly embed- 370,072, and in Norway May 11, 1929.

ded as indicated by 3 in the rock in front of the upstreamdam face 4:.

The water pressure on the tightening wall 2 is taken up by means of columns 5 of a suitable material, said columns being sufiicient- 1y thin to offer no resistance to contractions or expansions of the dam in a plane vertical to the axis of the columns.

Claim. I v

A permanent dam comprising the combination with a main concrete dam adapted to withstand all the load of the water pressure, of a thin water tightwall located a certain distance away from the upstream face of the dam, and means for supporting the thin wall against the dam including a number of independent columns adapted to yield in all directions in such a manner that the said thin wall is permitted to expand or contract in its own plane independent of the main dam.

In testimony whereof I afiix my signature.

CHRISTIAN FREDRIK GRfiNER. 

